A DIY mini water cutter is a fun science project to demonstrate the cutting power of pressurized water — not for cutting metal, but good for soft materials like paper, foam, or soft plastic.
Safety First!
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Never try to replicate industrial-level pressure (~30,000 psi) at home.
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This project uses moderate pressure only (~40–100 psi).
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Always wear safety goggles and work in a safe area.
🧰 Materials Needed:
| Item | Purpose |
|---|---|
| Plastic soda bottle (1L or 2L) | Water reservoir |
| Bicycle pump (with valve adapter) | To pressurize the bottle |
| Needle (or thin nozzle tip) | To create a fine jet |
| Tape / Glue gun | To secure nozzle |
| Water | Cutting medium |
| Thin sheet (foam, paper) | Material to cut |
🛠️ How to Build:
1. Prepare the Bottle
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Fill a 1L soda bottle halfway with water.
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Drill a tiny hole in the cap and insert a needle or small nozzle tip (use glue gun to seal it watertight).
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The smaller the hole, the higher the water jet speed.
2. Attach Bicycle Pump
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Fit the bicycle pump onto the bottle’s air space using a tire valve or airtight seal.
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Pressurize only to 40–60 psi (check with pump gauge).
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Over-pressurizing a plastic bottle is dangerous — stay well below 100 psi.
3. Cutting Action
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Aim the nozzle at a thin material (like paper, foam, or soft plastic).
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As you pump, pressure builds — then water sprays through the nozzle at high speed.
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You may notice it cuts or erodes the surface.
🧪 What You Can Demonstrate:
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Pressure and velocity relationship (Bernoulli’s principle)
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Effect of nozzle diameter on jet strength
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Difference between stream spray and focused cutting jet
📸 Optional Enhancements:
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Mount the bottle and target on a board for stability.
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Add colored water for better visibility.
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Try cutting wet clay, soft sponge, or cardboard with multiple trials.
🚫 What It Won’t Do:
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Cut hard materials like metal, wood, or glass.
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Replace real industrial water jet cutting.